Making a blueprint for Buildcraft and share it is very simple. For example, we'll make a Blueprint of this house :
We must use Marker from Buildcraft to enclose the structure. You can use regular Markers or the Markers from the Mod QuarryPlus (they work too). Main reason to use these is that the QuarryPlus markers can cover 256 x 256 if you use a Redstone signal.
You can use Angel Block from ExtraUtilities for the Height.
You can use only 3 Marker for the Ground. Click on the intersection to enable the Markers.
Next, place the Architect Table on the markers. You can use any side, but the orientation that you use with the Architect Table will be also used by the Builder.
The Architect Table have several options. The default are fine. But the Blocks options can be All or Simple. In Simple Mode, the Architect Table will only copy simple blocks such as stone, dirt, cobble. Complexe blocks can be chest or something like that.
Note : If you place something in a chest and make the Blueprint. The Builder will make the chest and he will place the items inside as well !
You can rename your blueprint of course.
You have created your Blueprint, but he's not shareable yet. If you want share it with the world, you must save in the Blueprint Library.
The first slot of the Blueprint Library save the Blueprint. The second slot is for loading the Blueprint. For this one in a new world, you put a Blank Blueprint, select your Blueprint in the list and voila.
Note : The Architect Table and the Blueprint Library don't need power.
Note : Your Blueprint's folder will be in the main folder of your Minecraft or instances.
Be careful when you copy massive structures because sometimes, you have to wait several hours to finish the Blueprint.